THÔNG BÁO
GS. Peter Egelhof sẽ đến thăm bộ môn và làm seminar về dạng detector cảm biến nhiệt để đo gamma phát bởi các mảnh phân hạch từ lò phản ứng hạt nhân
Thời gian : 9h30, 17/10 ( thứ hai)
Địa điểm : phòng F102
Content
Application of Calorimetric Low Temperature Detectors for the Investigation of Z-Yield Distributions of Fission Fragments and for other Research Topics
P. Egelhof
GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
Precise data on the characteristics of fission-fragment yields, element distributions, kinetic- energy distributions, excitation-energy distributions, and correlations of these quantities are of great interest for a better understanding of the fission process.
The new concept of calorimetric low temperature detectors (CLTD`s), which is based on the collection of phonons, provides considerable advantage over conventional heavy ion detectors, based on charge or photon collection, with respect to basic detector properties, and may therefore become a usefull tool for the investigation of fission fragments.
The operation principle of CLTD`s will be briefly discussed, and the design of dedicated detectors for heavy ions and their performance will be displayed. The advantages of such detectors are the more complete energy detection, the smaller energy gap of the detected quanta (phonons), leading to better counting statistics, and the absence of deadlayers and entrance windows. Therefore these detectors promise, and have already been demonstrated to provide high energy resolution, good energy linearity, low detection thresholds and insensitivity against radiation damage.
In a recent experiment, performed at the research reactor at ILL Grenoble, CLTD`s were applied for the first time for the investigation of Z-yield distributions of fission fragments. Fission fragments, produced by neutron induced fission of 235U, were mass separated with the LOHENGRIN separator, and then, after passing through a degrader foil, detected in an array of CLTD`s. A considerable advantage of the quality of Z-separation as compared to previous measurements with conventional ionization chambers was achieved, which allowed to reach the region of symmetry, not explored before. Preliminary data for the mass region 82 ≤ A ≤ 132 will be displayed, which have the potential to lead to a better understanding of the fission process, as well as of reactor neutrino oscillations and the reactor neutrino anomaly.
Finally, some other applications of CLTD`s, such as for accelerator mass spectroscopy, superheavy element research, stopping power measurements, Lambshift measurements, etc., will be briefly discussed.
